The Americans with Disabilities Act (ADA), which affects many public and private commercial buildings, is intended to ensure equal access to all persons regardless of physical disabilities. Section 309.4 of the ADA accessibility guidelines related to window and door hardware set forth that “[o]perable parts shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. The force required to activate operable parts shall be 5 pounds (22.2 N) maximum.” The Department of Justice Standards for Accessible Design (4.27.4) and the International Building Code (ANSI 309.4) set forth similar guidelines.
Architects prefer larger vents for exterior window designs to meet fresh air ventilation requirements. Using a larger quantity of smaller vents is typically more expensive than using a fewer quantity of larger vents. Additionally, current energy codes and specifications require low thermal insulating values for windows. Insulated glass has a better insulating value than metal, so the more metal used in a window system, the lower the insulating value. Because the exterior seal of a vent is subject to lower insulating values by nature and is a weak thermal point in the window system, a larger vent size helps to offset the overall insulating value due to the greater percentage of glass. A larger vent helps in the insulating performance but a larger vent takes more force to open.
Although using larger vents may improve insulating performance and decrease costs for architects, larger vents are typically more difficult to open and close. More specifically, an insulated glass unit weighs approximately seven (7) lbs. per square foot and can weigh as much as eight and one half (8.5) lbs. per square foot for laminated glass. When aluminum and other materials are added to construct the vent frame and sash, a vent can weigh around nine (9) lbs. per square foot. As such, a four (4) foot by five (5) foot vent may weigh approximately one hundred and eighty-nine (189) lbs. or more, which may be difficult to open using not more than five (5) lbs. of operational force as required by applicable ADA and other guidelines.
In addition to generally being more difficult to open and close, larger vents are also typically more difficult to lock and unlock. Vents, like other window systems, are manufactured and installed to meet strict air and water performance specifications. As such, to compress a sash to a vent frame of the window system, a great deal of compressive force can be needed to make the system air and water tight. The compression of the sash to the vent frame is commonly achieved by the locking of the sash using the vent handle, which moves one or more transmission bars inside a euro-grove (or vent track) around the perimeter of the sash when the vent handle is rotated in one direction.
For example, FIG. 1 is a diagram that illustrates an exemplary awning vent 100 with an exemplary locking mechanism as is known in the art. Referring to FIG. 1, the exemplary locking mechanism of the exemplary awning vent 100 may comprise, as an example, a handle 101, handle connectors 102, main transmission bars 103, transmission device connectors 104, 105, 110, corner transmission device housings 106, keepers 107, locking points 108, side transmission bars 109, and friction hinges 111. The handle 101 can attach to an inner portion of the sash. Certain components on an underside of the handle 101 may extend through the sash to an outer portion of the sash.
The handle connectors 102 may couple to the underside of the handle 101 at the outer portion of the sash and slidably fit in a euro-grove (not shown) that extends around an outer perimeter of the sash. Transmission bars 103 can attach to the handle connectors 102 at one end and corner transmission device connectors 104 at the other end, and may slidably fit in the euro-grove. The corner transmission device connectors 104 may slidably fit into corner transmission device housings 106. An outward, horizontal force on corner transmission device connectors 104 may cause the corner transmission device connectors 104 to extend into the corner transmission device housings 106, which in turn may cause the corner transmission device connectors 105 to extend vertically in the exemplary awning vent illustrated in FIG. 1.
Referring still to FIG. 1, side transmission bars 109 may attach to the corner transmission device connectors 105 at one end and transmission device connectors 110 at the other end, and may slidably fit in the euro-grove. Friction hinges 111 can attach to the sash and vent frame on both sides of the exemplary awning vent 100 and may be operable to guide and support the sash when venting as well as limit the opening range of the sash.
Locking points 108 may be attached to, or integrated with, one or more transmission bars 103, 109, or other components of the vent locking mechanism such as the transmission device connectors 104, 105, and 110, and may engage (or mate) with keepers 107, positioned at corresponding points on the vent frame, when moved by the handle 101 to the locking position. The engaging of the locking points 108 with the keepers 107 results in compression of the sash to the vent frame to make a tight seal. The larger the vent 100, the more locking points 108 and keepers 107 are needed to achieve an adequate seal. Further, the more locking points 108 and keepers 107, the more force is needed to lock and unlock the vent.
Many current vent designs for exterior windows require in excess of five (5) lbs. of force to open/close a sash. For example, many current vent designs do not use any mechanisms to open/close a sash (e.g., push open and pull closed), which may require more than five (5) lbs. of force, particularly for larger vents. Further, current vent designs that do have mechanisms for opening/closing a sash may not alleviate the force necessary to open/close the sash to meet the ADA guidelines. Instead, some mechanisms, such as cranks, not only may require more force to open, but also require excessive twisting. Additionally, many current vent designs for exterior windows require in excess of five (5) lbs. of force to lock/unlock a sash, particularly for larger vents having locking mechanisms with more locking points.
As such, there is a need for providing systems and methods for unlocking/locking and opening/closing windows without excessive force and twisting.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.